Dry phase reactor for generating medical isotopes

Abstract

An apparatus for generating medical isotopes provides for the irradiation of dry-phase, granular uranium compounds which are then dissolved in a solvent for separation of the medical isotope from the irradiated compound. Once the medical isotope is removed, the dissolved compound may be reconstituted in dry granular form for repeated irradiation.

What we claim is: 
     
       1. A method of producing medical isotopes using an apparatus having:
 a reactor chamber configured to control irradiation of material contained in the reaction chamber; 
 a plurality of containers that are together removably insertable into the chamber, wherein each respective container comprises container walls, wherein the container walls define an enclosed container interior, wherein the container interior includes a volume holding a dry granular uranium compound, wherein the reaction chamber is configured to control irradiation of dry granular uranium compound held in a container inserted into the reaction chamber, to cause generation of an isotope, wherein each respective container includes a cooling channel that passes through the container interior while being inwardly spaced from the container walls, wherein the cooling channel comprises tubing, wherein the tubing is configured to receive cooling fluid, wherein the tubing is configured to allow received cooling fluid to flow therein through the container interior while the cooling fluid is both in thermal contact with the dry granular uranium compound, and physically isolated from the contained dry granular uranium compound; and 
 a material processor having a separator operably configured to process the dry granular uranium compound by (a) dissolving the dry granular uranium in a solvent and then (b) separating the isotope from the granular uranium compound, the method comprising the steps of:
 (a) exposing a dry granular uranium compound to radiation to produce the medical isotope by nuclear reaction; 
 (b) dissolving the irradiated uranium compound in a solvent; and 
 (c) separating the medical isotope from the solventized uranium compound to provide an isolated medical isotope. 
 
 
     
     
       2. The method of  claim 1  wherein the uranium compound is selected from the group consisting of uranium oxides and uranium salts. 
     
     
       3. The method of  claim 1  wherein the uranium salt is selected from the group consisting of uranyl nitrite or uranyl sulfate. 
     
     
       4. The method of  claim 1  further including the step of (d) reconstituting the dry granular uranium compound by removing the solvent and repeating steps (a)-(c). 
     
     
       5. The method of  claim 1  wherein the solvent is an acid selected from the group consisting of nitric acid and sulfuric acid. 
     
     
       6. The method of  claim 1  further including the step of cooling the dry granular uranium compound by a flow of fluid in thermal physical contact with the granular uranium compound during step (a). 
     
     
       7. The method of  claim 1  wherein the medical isotope is  99 Mo. 
     
     
       8. The method of  claim 1  wherein in step (a) the dry granular uranium compound is held in multiple containers and wherein step (b) dissolves the irradiated uranium compound in the solvent in the containers and then removes the solvent from the containers along with the dissolved uranium compound. 
     
     
       9. The method of  claim 1  further including placement of one or more reflectors reflecting radiation near the dry granular uranium compound during irradiation. 
     
     
       10. The method of  claim 1  including the step of moving neutron absorbing control elements in a region near the dry granular uranium compound during irradiation to maintain critical reaction during step (a). 
     
     
       11. The method of  claim 1  wherein the radiation is produced by an electrically powered neutron generator irradiating the dry granular uranium compound in a sub-critical reactor. 
     
     
       12. An apparatus for producing medical isotopes comprising:
 a reaction chamber configured to control irradiation of material contained in the reaction chamber; 
 a plurality of containers that are together removably insertable into the reaction chamber, 
 wherein each respective container comprises container walls,
 wherein the container walls define an enclosed container interior,
 wherein the container interior includes a volume holding a dry granular uranium compound,
 wherein the reaction chamber is configured to control irradiation of dry granular uranium compound held in a container inserted into the reaction chamber, to cause generation of an isotope, 
 
 
 
 wherein each respective container includes a cooling channel that passes through the container interior while being inwardly spaced from the container walls,
 wherein the cooling channel comprises tubing,
 wherein the tubing is configured to receive cooling fluid, 
 wherein the tubing is configured to allow received cooling fluid to flow therein through the container interior while the cooling fluid is both
 in thermal contact with the dry granular uranium compound, and 
 physically isolated from the contained dry granular uranium compound; and 
 
 
 
 a material processor having a separator operably configured to process the dry granular uranium compound by (a) dissolving the dry granular uranium in a solvent, and then (b) separating the isotope from the granular uranium compound. 
 
     
     
       13. The apparatus of  claim 12  wherein each respective container includes a second channel comprising tubing wherein the tubing is configured to allow a received stream of water to pass into the container interior while the stream of water is in contact with the dry granular uranium compound to dissolve and flush the dry granular uranium compound from the container. 
     
     
       14. The apparatus of  claim 12  wherein each respective container includes at least one barrier for distributing the dry, granular uranium compound into a geometrical configuration that does not support sustained nuclear reaction. 
     
     
       15. The apparatus of  claim 12  further including one or more reflectors reflecting radiation near the dry granular uranium compound during irradiation. 
     
     
       16. The apparatus of  claim 12  wherein the uranium compound is selected from a group consisting of uranium oxides and uranium salts. 
     
     
       17. The apparatus of  claim 16  wherein the uranium salt is selected from the group consisting of uranyl nitrite or uranyl sulfate. 
     
     
       18. The apparatus of  claim 12  wherein the solvent is an acid selected from a group consisting of nitric acid and sulfuric acid. 
     
     
       19. The apparatus of  claim 12  wherein the containers are arranged in at least two concentric rings.